The photoreduction of carbon dioxide (CO₂) to solar fuels is meaningful in many fields relevant to CO₂ emission control, solar energy conversion and storage, carbon-neutral fuel production, CO₂ conversion, and carbon cycle closure. The CO₂ photoreduction on TiO₂ nanotube arrays using concentrated sunlight under favorable photothermal conditions is considered in this work. TiO₂ is a typical catalyst for the process while the reaction rate is still kept at rather poor level, partly because of the mild reaction conditions employed. In this study, the TiO₂ photocatalyst was shaped as nanotube arrays and the current process limitations were tackled by raising the incident light intensity and reaction temperature by using concentrating solar light (concentration ratio between 200 and 800), while jointly increasing the achievable H₂O and CO₂ partial pressure. The results showed that the rate of CO₂ photoreduction on the TiO₂ nanotube array was increased by hundred times. The use of concentrated solar light heightens the hydrocarbons production rate to thousand μmol g⁻¹ h⁻¹ and enriches hydrocarbons products to CH₄, C₂H₄, and C₂H₆. The favorable effects on enhancing the catalyst performance were ascribed to the intensification of reaction conditions. This noticeable breakthrough may represent an important step forward in the deployment of CO₂ photoreduction technologies.

中文翻译：

---

在聚光太阳光驱动的有利光热条件下，使用 TiO2 纳米管阵列具有显着的 CO2 光还原活性

将二氧化碳 (CO ₂ ) 光还原为太阳能燃料在与 CO ₂排放控制、太阳能转换和存储、碳中性燃料生产、CO ₂转换和碳循环闭合相关的许多领域中具有重要意义。在这项工作中考虑了在有利的光热条件下使用集中的阳光在TiO ₂纳米管阵列上进行CO _{2 光}还原。TiO ₂是该方法的典型催化剂，而反应速率仍然保持在相当低的水平，部分原因是所采用的反应条件温和。在本研究中，TiO ₂光催化剂被塑造成纳米管阵列，通过使用聚光太阳光（浓度比在 200 和 800 之间）提高入射光强度和反应温度，同时共同增加可实现的 H ₂ O 和 CO ₂分压，解决了当前工艺限制。结果表明，TiO ₂纳米管阵列上的CO _{2 光}还原速率提高了数百倍。使用会聚的太阳光的加剧烃生产速率以千μ摩尔克^-1 ħ ^-1，丰富的烃产品，以CH ₄，C ₂ H ^ ₄，和C₂小时₆。提高催化剂性能的有利影响归因于反应条件的强化。这一显着的突破可能代表着部署 CO _{2 光}还原技术向前迈出的重要一步。